1. Field of the Invention
The present invention relates to a honeycomb structured body.
2. Discussion of the Background
In recent years, particulates such as soot and the like contained in exhaust gases discharged from internal combustion engines of vehicles, such as buses and trucks, and construction machines, have raised serious problems as those particulates are harmful to the environment and the human body.
There have been proposed various honeycomb structured bodies made from porous ceramics, which serve as filters capable of capturing particulates in exhaust gases to purify the exhaust gases.
Conventionally, with respect to the honeycomb structured body of this type, JP-A 2002-219319 has disclosed a filter made from porous cordierite, in which a number of through holes, each having either one of ends being sealed, extend in a longitudinal direction with a partition wall interposed therebetween so that a number of cells are formed, and this filter (porous cordierite) has a pore distribution of the following ratio: pore volume of pores having a pore diameter of less than 10 μm: 15% or less of the entire pore volume, pore volume of pores having a pore diameter in a range of 10 to 50 μm: 75% or more of the entire pore volume, and pore volume of pores having a pore diameter exceeding 50 μm: 10% or less of the entire pore volume.
JP-A 2002-219319 describes that, as the effects of the filter, the particulate capture efficiency is improved and it is possible to prevent the increase in pressure loss due to clogging of the pores with the particulates.
JP-A 2002-357114 discloses an exhaust gas purifying filter having the same structure as that of JP-A 2002-219319, in which a catalyst used for oxidizing and removing particulates is adhered to a partition wall, the porosity is set in a range of 55 to 80%, the average pore diameter is set in a range of 30 to 50 μm and the pore volume of pores having a pore diameter of 100 μm or more is set to 5% or less of the entire pore volume.
The contents of JP-A 2002-219319, JP-A 2002-357114 are incorporated herein by reference in their entirety.